Bed cover help or hurt gas mileage?

[macx]

I've been a die hard hot rodder all my life and always tweak vehicles
for more performance.

Purposely restraining myself with this 93 2.3 5 speed I bought recently
after my car got stolen.

Concentrating more on correcting all the problems caused by horrible
neglect, finally have it in pretty darn good mechanical condition.

NOW - I'd like to have a bed cover for a number of reasons.

Am curious - have read posts swearing that a bed cover actually
reduced gas mileage, but I would sure think it would help by
reducing turbulence in the bed and maybe also by preventing air
getting trapped in front of the upper part of the end gate.

Anybody have any actual before and after comparisons?

Thanks!

 

[wrecking-crew]

Should help. They used a similar Ranger on Mythbusters and gained from it.

 

[LIMA BEAN]

Should help. They used a similar Ranger on Mythbusters and gained from it.

Nope they busted it 2nd time around.



I wondered why they didnt use a flow meter first time around, I have one in my jet-boat and love it.

 

[rockin86ranger]

I've had them help on everything i've put them on.

 

[Snoranger]

I tracked my MPGs on every truck I've ever owned (8 total, 4 had tonneau covers, over 17 years) on every tank of fuel.

I've seen about a 1 - 1.5 MPG gain with the tonneau cover on.

 

[Gotta_gofast]

At highway speeds my scangauge shows minimal (but less) load on the engine usually. I have a fiberglass tonneau which adds a little weight over the rear axle. It rides better, locks for security, looks nicer, and provides a little better traction in snow and other sloppyness.

 

[macx]

That's good info - thanks!

Nothing like (carefully monitored) experience.

 

[Gotta_gofast]

If that hotrod bug ever bites, its pretty easy to do a turbo 2.3L swap in your truck!

 

[85_Ranger4x4]

IMO the longer the box the more of a difference it makes.

I still have leaves swirling in my 6.5" F-150 box from last fall, my brother has had pop bottles blown out of his 8' box.

 

[Snoranger]

A slider back window also changes things.

How many of us have opened the back slider, only to get a bunch of leaves hit the windshield and disappear into the dash? That shows a change in the airflow in the bed that may be enough to effect the MPG.

 

[JohnnyO]

My old 3.0 Ranger was too slow to get out of its own way but I noticed on the highway that it held speed better with the tonneau.
The problem I have with the Mythbusters episode is that they used full-sized crew cab pickups with short beds, where a lot of the air is going to go past the bed because the cab is longer than the bed is. On a regular cab truck with a normal bed, more air is going to hit the bed so I think a tonneau will help.
Also it keeps your stuff dry.

 

[doorgunner]

Whether MythBusters likes it or not.....I've always gotten better mpg with the tailgate down on the highway...I'd think a light-weight cover could only help.....

 

[LIMA BEAN]

You cant argue with their data under the controled conditions. The redneck science of saying oh um well i stuffed this much gas in, drove in the mountains a bit, the desert the next with stop and go and idling, warm up times, just one person in the car one time and an 500 pnd load the next, different weather and air densities, headwinds, tailwinds, cross winds, drafting other vehicles or being drafted for long periods, straight roads, curvy roads, varying speeds then went and refilled and used gallons/ish from different gas pumps and different gas brands and odometer to come to a Billy Bob Nye the science guy grand conclusion. Wrong! to many variables, mythbusters is right.

 

[straycat]

Tonneau covers do help. The flatter they fit on the bed the better. I do have several buddies with compact and full size trucks that travel a lot and they claim the covers help save gas on the highway. They keep telling me the gas receipts prove it. I don't have one. I drive with the tailgate up and I get 24 mpg on the highway not packing a heavy load with my 2wd Ranger running
BFG KO 33's. Maybe I should get one to see if I get another 1 or 2 mpg.....

 

[Snoranger]

You cant argue with their data under the controled conditions. The redneck science of saying oh um well i stuffed this much gas in, drove in the mountains a bit, the desert the next with stop and go and idling, warm up times, just one person in the car one time and an 500 pnd load the next, different weather and air densities, headwinds, tailwinds, cross winds, drafting other vehicles or being drafted for long periods, straight roads, curvy roads, varying speeds then went and refilled and used gallons/ish from different gas pumps and different gas brands and odometer to come to a Billy Bob Nye the science guy grand conclusion. Wrong! to many variables, mythbusters is right.

So, them running a few test is better then me tracking my fuel mileage for 10 years on the same truck, running the same route, and finding almost the exact same story every tank of gas? (cover on, 1 - 1.5MPG better.)

I dont think so. Its not some redneck, backyard science. Its 10 years of research.